It is very common for people with ME/CFS to be told by medical professionals as well as friends and family that there is nothing wrong with them, or that it’s “all in your head.”
I personally experienced this right from the start: the landlord at my cooperative housing community invalidated my inability to work more or contribute more to the social life at the house, necessitating my moving out. One of my coaches insisted that my continued inability to exercise was simply due to loss of fitness, before gradually ceasing communicating at all. My medical doctor referred me to an experimental “therapeutic treatment” for hypochondriasis. Family members suggested that antidepressants would probably resolve my symptoms.
The harm done by this kind of invalidation cannot be overstated.
It is my commitment as a coach to never doubt an athlete who tells me they are tired, or think something is wrong. The same should apply when someone confides ill-health in any circumstance. Our own bodies have enormous wisdom, and someone who is trying to tune into that wisdom should be supported wholeheartedly by those whom they confide in. This goes so far beyond the bare minimum of believing they’re not faking it; it also means that if help or suggestions are offered, they should be given in ways that validate the individual’s experience rather than minimizing it.